1 /* STMicroelectronics STMPE811 Touchscreen Driver 2 * 3 * (C) 2010 Luotao Fu <l.fu@pengutronix.de> 4 * All rights reserved. 5 * 6 * This program is free software; you can redistribute it and/or modify it 7 * under the terms of the GNU General Public License as published by the 8 * Free Software Foundation; either version 2 of the License, or (at your 9 * option) any later version. 10 * 11 */ 12 13 #include <linux/kernel.h> 14 #include <linux/module.h> 15 #include <linux/sched.h> 16 #include <linux/interrupt.h> 17 #include <linux/init.h> 18 #include <linux/device.h> 19 #include <linux/platform_device.h> 20 #include <linux/input.h> 21 #include <linux/slab.h> 22 #include <linux/delay.h> 23 #include <linux/i2c.h> 24 #include <linux/workqueue.h> 25 26 #include <linux/mfd/stmpe.h> 27 28 /* Register layouts and functionalities are identical on all stmpexxx variants 29 * with touchscreen controller 30 */ 31 #define STMPE_REG_INT_STA 0x0B 32 #define STMPE_REG_ADC_CTRL1 0x20 33 #define STMPE_REG_ADC_CTRL2 0x21 34 #define STMPE_REG_TSC_CTRL 0x40 35 #define STMPE_REG_TSC_CFG 0x41 36 #define STMPE_REG_FIFO_TH 0x4A 37 #define STMPE_REG_FIFO_STA 0x4B 38 #define STMPE_REG_FIFO_SIZE 0x4C 39 #define STMPE_REG_TSC_DATA_XYZ 0x52 40 #define STMPE_REG_TSC_FRACTION_Z 0x56 41 #define STMPE_REG_TSC_I_DRIVE 0x58 42 43 #define OP_MOD_XYZ 0 44 45 #define STMPE_TSC_CTRL_TSC_EN (1<<0) 46 47 #define STMPE_FIFO_STA_RESET (1<<0) 48 49 #define STMPE_IRQ_TOUCH_DET 0 50 51 #define SAMPLE_TIME(x) ((x & 0xf) << 4) 52 #define MOD_12B(x) ((x & 0x1) << 3) 53 #define REF_SEL(x) ((x & 0x1) << 1) 54 #define ADC_FREQ(x) (x & 0x3) 55 #define AVE_CTRL(x) ((x & 0x3) << 6) 56 #define DET_DELAY(x) ((x & 0x7) << 3) 57 #define SETTLING(x) (x & 0x7) 58 #define FRACTION_Z(x) (x & 0x7) 59 #define I_DRIVE(x) (x & 0x1) 60 #define OP_MODE(x) ((x & 0x7) << 1) 61 62 #define STMPE_TS_NAME "stmpe-ts" 63 #define XY_MASK 0xfff 64 65 struct stmpe_touch { 66 struct stmpe *stmpe; 67 struct input_dev *idev; 68 struct delayed_work work; 69 struct device *dev; 70 u8 sample_time; 71 u8 mod_12b; 72 u8 ref_sel; 73 u8 adc_freq; 74 u8 ave_ctrl; 75 u8 touch_det_delay; 76 u8 settling; 77 u8 fraction_z; 78 u8 i_drive; 79 }; 80 81 static int __stmpe_reset_fifo(struct stmpe *stmpe) 82 { 83 int ret; 84 85 ret = stmpe_set_bits(stmpe, STMPE_REG_FIFO_STA, 86 STMPE_FIFO_STA_RESET, STMPE_FIFO_STA_RESET); 87 if (ret) 88 return ret; 89 90 return stmpe_set_bits(stmpe, STMPE_REG_FIFO_STA, 91 STMPE_FIFO_STA_RESET, 0); 92 } 93 94 static void stmpe_work(struct work_struct *work) 95 { 96 int int_sta; 97 u32 timeout = 40; 98 99 struct stmpe_touch *ts = 100 container_of(work, struct stmpe_touch, work.work); 101 102 int_sta = stmpe_reg_read(ts->stmpe, STMPE_REG_INT_STA); 103 104 /* 105 * touch_det sometimes get desasserted or just get stuck. This appears 106 * to be a silicon bug, We still have to clearify this with the 107 * manufacture. As a workaround We release the key anyway if the 108 * touch_det keeps coming in after 4ms, while the FIFO contains no value 109 * during the whole time. 110 */ 111 while ((int_sta & (1 << STMPE_IRQ_TOUCH_DET)) && (timeout > 0)) { 112 timeout--; 113 int_sta = stmpe_reg_read(ts->stmpe, STMPE_REG_INT_STA); 114 udelay(100); 115 } 116 117 /* reset the FIFO before we report release event */ 118 __stmpe_reset_fifo(ts->stmpe); 119 120 input_report_abs(ts->idev, ABS_PRESSURE, 0); 121 input_sync(ts->idev); 122 } 123 124 static irqreturn_t stmpe_ts_handler(int irq, void *data) 125 { 126 u8 data_set[4]; 127 int x, y, z; 128 struct stmpe_touch *ts = data; 129 130 /* 131 * Cancel scheduled polling for release if we have new value 132 * available. Wait if the polling is already running. 133 */ 134 cancel_delayed_work_sync(&ts->work); 135 136 /* 137 * The FIFO sometimes just crashes and stops generating interrupts. This 138 * appears to be a silicon bug. We still have to clearify this with 139 * the manufacture. As a workaround we disable the TSC while we are 140 * collecting data and flush the FIFO after reading 141 */ 142 stmpe_set_bits(ts->stmpe, STMPE_REG_TSC_CTRL, 143 STMPE_TSC_CTRL_TSC_EN, 0); 144 145 stmpe_block_read(ts->stmpe, STMPE_REG_TSC_DATA_XYZ, 4, data_set); 146 147 x = (data_set[0] << 4) | (data_set[1] >> 4); 148 y = ((data_set[1] & 0xf) << 8) | data_set[2]; 149 z = data_set[3]; 150 151 input_report_abs(ts->idev, ABS_X, x); 152 input_report_abs(ts->idev, ABS_Y, y); 153 input_report_abs(ts->idev, ABS_PRESSURE, z); 154 input_sync(ts->idev); 155 156 /* flush the FIFO after we have read out our values. */ 157 __stmpe_reset_fifo(ts->stmpe); 158 159 /* reenable the tsc */ 160 stmpe_set_bits(ts->stmpe, STMPE_REG_TSC_CTRL, 161 STMPE_TSC_CTRL_TSC_EN, STMPE_TSC_CTRL_TSC_EN); 162 163 /* start polling for touch_det to detect release */ 164 schedule_delayed_work(&ts->work, HZ / 50); 165 166 return IRQ_HANDLED; 167 } 168 169 static int __devinit stmpe_init_hw(struct stmpe_touch *ts) 170 { 171 int ret; 172 u8 adc_ctrl1, adc_ctrl1_mask, tsc_cfg, tsc_cfg_mask; 173 struct stmpe *stmpe = ts->stmpe; 174 struct device *dev = ts->dev; 175 176 ret = stmpe_enable(stmpe, STMPE_BLOCK_TOUCHSCREEN | STMPE_BLOCK_ADC); 177 if (ret) { 178 dev_err(dev, "Could not enable clock for ADC and TS\n"); 179 return ret; 180 } 181 182 adc_ctrl1 = SAMPLE_TIME(ts->sample_time) | MOD_12B(ts->mod_12b) | 183 REF_SEL(ts->ref_sel); 184 adc_ctrl1_mask = SAMPLE_TIME(0xff) | MOD_12B(0xff) | REF_SEL(0xff); 185 186 ret = stmpe_set_bits(stmpe, STMPE_REG_ADC_CTRL1, 187 adc_ctrl1_mask, adc_ctrl1); 188 if (ret) { 189 dev_err(dev, "Could not setup ADC\n"); 190 return ret; 191 } 192 193 ret = stmpe_set_bits(stmpe, STMPE_REG_ADC_CTRL2, 194 ADC_FREQ(0xff), ADC_FREQ(ts->adc_freq)); 195 if (ret) { 196 dev_err(dev, "Could not setup ADC\n"); 197 return ret; 198 } 199 200 tsc_cfg = AVE_CTRL(ts->ave_ctrl) | DET_DELAY(ts->touch_det_delay) | 201 SETTLING(ts->settling); 202 tsc_cfg_mask = AVE_CTRL(0xff) | DET_DELAY(0xff) | SETTLING(0xff); 203 204 ret = stmpe_set_bits(stmpe, STMPE_REG_TSC_CFG, tsc_cfg_mask, tsc_cfg); 205 if (ret) { 206 dev_err(dev, "Could not config touch\n"); 207 return ret; 208 } 209 210 ret = stmpe_set_bits(stmpe, STMPE_REG_TSC_FRACTION_Z, 211 FRACTION_Z(0xff), FRACTION_Z(ts->fraction_z)); 212 if (ret) { 213 dev_err(dev, "Could not config touch\n"); 214 return ret; 215 } 216 217 ret = stmpe_set_bits(stmpe, STMPE_REG_TSC_I_DRIVE, 218 I_DRIVE(0xff), I_DRIVE(ts->i_drive)); 219 if (ret) { 220 dev_err(dev, "Could not config touch\n"); 221 return ret; 222 } 223 224 /* set FIFO to 1 for single point reading */ 225 ret = stmpe_reg_write(stmpe, STMPE_REG_FIFO_TH, 1); 226 if (ret) { 227 dev_err(dev, "Could not set FIFO\n"); 228 return ret; 229 } 230 231 ret = stmpe_set_bits(stmpe, STMPE_REG_TSC_CTRL, 232 OP_MODE(0xff), OP_MODE(OP_MOD_XYZ)); 233 if (ret) { 234 dev_err(dev, "Could not set mode\n"); 235 return ret; 236 } 237 238 return 0; 239 } 240 241 static int stmpe_ts_open(struct input_dev *dev) 242 { 243 struct stmpe_touch *ts = input_get_drvdata(dev); 244 int ret = 0; 245 246 ret = __stmpe_reset_fifo(ts->stmpe); 247 if (ret) 248 return ret; 249 250 return stmpe_set_bits(ts->stmpe, STMPE_REG_TSC_CTRL, 251 STMPE_TSC_CTRL_TSC_EN, STMPE_TSC_CTRL_TSC_EN); 252 } 253 254 static void stmpe_ts_close(struct input_dev *dev) 255 { 256 struct stmpe_touch *ts = input_get_drvdata(dev); 257 258 cancel_delayed_work_sync(&ts->work); 259 260 stmpe_set_bits(ts->stmpe, STMPE_REG_TSC_CTRL, 261 STMPE_TSC_CTRL_TSC_EN, 0); 262 } 263 264 static int __devinit stmpe_input_probe(struct platform_device *pdev) 265 { 266 struct stmpe *stmpe = dev_get_drvdata(pdev->dev.parent); 267 struct stmpe_platform_data *pdata = stmpe->pdata; 268 struct stmpe_touch *ts; 269 struct input_dev *idev; 270 struct stmpe_ts_platform_data *ts_pdata = NULL; 271 int ret; 272 int ts_irq; 273 274 ts_irq = platform_get_irq_byname(pdev, "FIFO_TH"); 275 if (ts_irq < 0) 276 return ts_irq; 277 278 ts = kzalloc(sizeof(*ts), GFP_KERNEL); 279 if (!ts) { 280 ret = -ENOMEM; 281 goto err_out; 282 } 283 284 idev = input_allocate_device(); 285 if (!idev) { 286 ret = -ENOMEM; 287 goto err_free_ts; 288 } 289 290 platform_set_drvdata(pdev, ts); 291 ts->stmpe = stmpe; 292 ts->idev = idev; 293 ts->dev = &pdev->dev; 294 295 if (pdata) 296 ts_pdata = pdata->ts; 297 298 if (ts_pdata) { 299 ts->sample_time = ts_pdata->sample_time; 300 ts->mod_12b = ts_pdata->mod_12b; 301 ts->ref_sel = ts_pdata->ref_sel; 302 ts->adc_freq = ts_pdata->adc_freq; 303 ts->ave_ctrl = ts_pdata->ave_ctrl; 304 ts->touch_det_delay = ts_pdata->touch_det_delay; 305 ts->settling = ts_pdata->settling; 306 ts->fraction_z = ts_pdata->fraction_z; 307 ts->i_drive = ts_pdata->i_drive; 308 } 309 310 INIT_DELAYED_WORK(&ts->work, stmpe_work); 311 312 ret = request_threaded_irq(ts_irq, NULL, stmpe_ts_handler, 313 IRQF_ONESHOT, STMPE_TS_NAME, ts); 314 if (ret) { 315 dev_err(&pdev->dev, "Failed to request IRQ %d\n", ts_irq); 316 goto err_free_input; 317 } 318 319 ret = stmpe_init_hw(ts); 320 if (ret) 321 goto err_free_irq; 322 323 idev->name = STMPE_TS_NAME; 324 idev->id.bustype = BUS_I2C; 325 idev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS); 326 idev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH); 327 328 idev->open = stmpe_ts_open; 329 idev->close = stmpe_ts_close; 330 331 input_set_drvdata(idev, ts); 332 333 input_set_abs_params(idev, ABS_X, 0, XY_MASK, 0, 0); 334 input_set_abs_params(idev, ABS_Y, 0, XY_MASK, 0, 0); 335 input_set_abs_params(idev, ABS_PRESSURE, 0x0, 0xff, 0, 0); 336 337 ret = input_register_device(idev); 338 if (ret) { 339 dev_err(&pdev->dev, "Could not register input device\n"); 340 goto err_free_irq; 341 } 342 343 return ret; 344 345 err_free_irq: 346 free_irq(ts_irq, ts); 347 err_free_input: 348 input_free_device(idev); 349 platform_set_drvdata(pdev, NULL); 350 err_free_ts: 351 kfree(ts); 352 err_out: 353 return ret; 354 } 355 356 static int __devexit stmpe_ts_remove(struct platform_device *pdev) 357 { 358 struct stmpe_touch *ts = platform_get_drvdata(pdev); 359 unsigned int ts_irq = platform_get_irq_byname(pdev, "FIFO_TH"); 360 361 stmpe_disable(ts->stmpe, STMPE_BLOCK_TOUCHSCREEN); 362 363 free_irq(ts_irq, ts); 364 365 platform_set_drvdata(pdev, NULL); 366 367 input_unregister_device(ts->idev); 368 369 kfree(ts); 370 371 return 0; 372 } 373 374 static struct platform_driver stmpe_ts_driver = { 375 .driver = { 376 .name = STMPE_TS_NAME, 377 .owner = THIS_MODULE, 378 }, 379 .probe = stmpe_input_probe, 380 .remove = __devexit_p(stmpe_ts_remove), 381 }; 382 383 static int __init stmpe_ts_init(void) 384 { 385 return platform_driver_register(&stmpe_ts_driver); 386 } 387 388 module_init(stmpe_ts_init); 389 390 static void __exit stmpe_ts_exit(void) 391 { 392 platform_driver_unregister(&stmpe_ts_driver); 393 } 394 395 module_exit(stmpe_ts_exit); 396 397 MODULE_AUTHOR("Luotao Fu <l.fu@pengutronix.de>"); 398 MODULE_DESCRIPTION("STMPEXXX touchscreen driver"); 399 MODULE_LICENSE("GPL"); 400 MODULE_ALIAS("platform:" STMPE_TS_NAME); 401